Means for handling freshly galvanized pipe during internal swabbing



W. S. PEARSON MEANS FOR HANDLING FRESHLY GALVANIZED PIPE DURING INTERNAL SWABBING July 10. 1956 2 Sheets-Sheet 1 Filed Oct. 5, 1950 12775 TZZUT William 5. Pearson -.%,22; A/W fizz July 10. 1956 w. s. PEARSON MEANS FOR HANDLING FRESHLY GALVANIZED PIPE DURING INTERNAL SWABBING 2 Sheets-Sheet 2 Filed Oct. 5, 1950 Wz'Z/z'am 5. Pearson b q Jfl 5177 75 United States Patent MEANS FOR HANDLING FRESHLY GALVAN- IZED PIPE DURING INTERNAL SWABBING William S. Pearson, Baltimore, Md., assignor, by mesne assignments, to C. C. Corporation, a corporation of Maryland Application October 5, 1950, Serial No. 188,622

6 Claims. (Cl. 118-60) The present invention relates to improvements in means for handling freshly galvanized pipe during internal swabbing to remove excess galvanizing metal from the internal walls of the pipe.

An important object of the present invention is to provide improved means for holding an end of a freshly galvanized pipe or conduit section firmly in the mouth of a blow tube while heated swabbing fluid is blown into and through the interior of the pipe to expel excess galvanizing fluid therefrom.

Another object of the invention is to provide improved intermittently operable pinch roll means adapted to operate momentarily in coordination with other freshly galvanized conduit handling mechanism as a supplementary supporting and driving expedient.

A further object of the invention is to provide an improved separable pipe-supporting and motivating pinch roll assembly adapted for use in apparatus for handling freshly galvanized pipe during removal of excess galvanizing material therefrom.

Other objects, features and. advantages of the present invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying drawings in which:

Figure l is a more or less schematic elevational view of an apparatus for removing excess galvanizing material from freshly galvanized pipe or conduit, and utilizing the present invention; and

Figure 2 is a more or less schematic view on an enlarged scale taken substantially on the line II-II of Fig. 1, showing certain parts in section and others in elevation in the separable conduit-supporting and motivating pinch roll assembly.

An apparatus for removing excess galvanizing material from freshly galvanized pipe or conduit, as shown in Fig. 1, comprises a pair of magnetic overhead conveyor rolls 5 supported by a framework 7 adjacent to a zinc tank or pot 8 from the galvanizing bath in which successive freshly galvanized conduit sections 9 are lifted by an attendant and delivered to the undersides of the conveyor rolls 5 which thereupon support the same and impel the freshly galvanized conduit longitudinally forwardly through respective aligned openings in the sides of a spatter chamber 10. Means for driving the conveyor rolls 5 comprise a motor 11 mounted on the spatter chamber and suitably drivingly connected with the conveyor rolls through means such as a chain drive 12. As the hot, freshly galvanized conduit sections emerge from the side of the spatter chamber beyond the conveyor rolls '5, the sections pass progressively through a ring swab 13 from which encircling jets of heated swabbing fluid such as superheated steam are impinged upon the external surface of the pipe to swab excess galvanizing fluid therefrom and drive the excess galvanizing fluid into the spatter chamber 10.

Immediately after traveling beyond the external swab 13, the pipe section 9 is engaged between a pair of pinch ice rolls 14 which support and impel the conduit section onward toward and successively into engagement with spaced overhead magnetic conveyor rolls 15 which through the medium of a chain drive 17 are actuated by the motor 11. As will be observed, the path of movement of the conduit section 9 is in a diagonally upward direction so as to facilitate the swabbing process.

After the pipe section 9 undergoing swabbing has been moved by the pinch rolls 14 and the conveyor rolls 15 to a position where only the trailing extremity portion of the pipe remains inside the spatter chamber 10, the conduit or pipe section is released from the conveyor rolls 15 by deenergization of the rolls, and the forward end portion of the conduit section is received in the mouth of a gooseneck blow tube 18 through which a charge or blast of internal swabbing fluid such as superheated steam is driven into and through the interior of the pipe 9 to swab and eject excess galvanizing material therefrom into the spatter chamber 10.

One of the functions of the pinch rolls 14 is to maintain endwise forward pressure on the pipe 9 while it is in the mouth of the blow tube 18 and for this purpose the pinch rolls 14 are motivated by suitable chain drive from the motor 11 through the medium of a slip clutch arrangement of suitable character which will maintain the pinch rolls in operation until predetermined resistance to forward movement of the engaged pipe 9 is encountered whereupon the slip clutch operates to permit the rolls to remain in stationary engagement with forward pressure on the pipe.

However, it has been found that if sutficient resistance to slippage is built into the slip clutch for the pinch rolls 14 to maintain adequate forward pressure on the pipe 9 to hold the forward end thereof in the mouth of the blow tube 18 with suflicientfirmness to avoid displacement thereof from the blow tube mouth and consequent avoidance of leakage and loss of swabbing fluid force, there is undue likelihood of slippage and damage to the external surface of the freshly galvanized pipe where it is gripped by the pinch rolls 14.

Therefore, there is provided by the present invention additional means for engaging and impelling the freshly galvanized pipe 9, or at least urging the pipe 9 into the mouth of the blow tube 18 with sufiicient force, supplemental to the force applied thereto by means of the pinch rolls 14 to assure freedom from reverse displacement of the tube from firm engagement within the blow tube mouth when the force of the internal swabbing fluid is released into the pipe. Herein such additional means comprises an assembly 20 supported by the framework 7 as near as practicable to the head of the blow tube 18 and including a pair of cooperable pinch rolls 21 and 22 disposed to engage the pipe section 9 therebetween after the same has been released from the overhead conveyor rolls 15 and for imparting to the pipe section forward thrust supplemental to the forward thrust of the first mentioned pinch rolls 14 which engage the trailing end portion of the pipe.

in a practical form, the auxiliary thrust imparting mechanism 29 comprises a roll-supporting framework including an upright or standard 23 for supporting the pinch roll 21 and an upright or standard 24 for supporting the pinch roll 22 (Fig. 2). The standards 23 and 2e are secured by means of respective angle brackets 25 to the respective upper side portions of the frame 7 so as to support the pinch rolls 21 and 22 on respectively opposite sides of the path of movement of the pipe section 9 to be swabbed. By preference the standards 23 and 24 are insulated from the framework 7 by means of insulating material 27 interposed between the brackets 25 and the respective standards, the insulating material being 3 either for vibration insulation or electrical insulation or both.

Each of the pinch rolls 21 and 22 is directly carried by a respective elongated shaft 28 to the lower end of which the pinch roll is appropriately secured while the upper end of the shaft is supported by a rocker bearing 29 mounted on a bracket 36 secured to the upper end portion of the respective standards 23 and 24. Through this arrangement, a small rocking movement in the bear- Lng 29 affords relatively large swinging leverage movement of the lower end portion of the respective roll shaft 28.

The position of one of the pinch rolls 21 or 22, in the present instance of the pinch roll 22 is adjustably maintained in transverse relation to the path of movement of the pipe sections 9 by means of an arm or rod 31 having a bearing 32 thereon in engagement with the adjacent shaft 28 for the roll 22 adjacent the lower end portion of the roll shaft. The outer end portion of the rod 31 is attached to the standard 24 for longitudinal adjustment which is fixedly maintained by means such as lock nuts 33. Through this arrangement the pinch roll 22 can be accurately adjusted transversely of the path of movement of the pipe sections 9 by manipulation of the adjustment and retaining rod 31 for accommodating various sizes of pipe. In the adjustment the shaft 28 for the roll 22 rocks about the support provided by the bearing 29.

Rotation of the pinch rolls 21 and 22 in unison is effected by means such as meshing large tooth gears 34 carried by the respective shafts 28 adjacent to the upper ends of the shaft close to the supporting rocker bearings 29. Hence, substantial relative adjustment in the spacing between the pinch rolls 21 and 22 can be effected without interfering with the proper meshing of the gears 34 to drive the shafts 23 and thus the pinch rolls in unison in respectively opposite directions.

Means for driving the pinch rolls comprises a motor 35 which is drivingly connected through a gear train 37 with the drive shaft 28 of one of the pinch rolls, herein of the pinch roll 21. Here, again, the gear connection is effected adjacent to the upper end of the shaft assembly so that minimum interference with proper meshing of the transmission gears will occur throughout the range of relative spacing adjustment of the pinch rolls.

The arrangement and construction of the auxiliary pinch roll assembly is such that the pinch rolls 21 and 22 remain separated sufflciently to permit free movement of the pipe section 9 to be swabbed therebetween under the influence of the conveyor rolls 15 until the conveyor rolls 15 are deenergized and release the conduit section. Thereupon, the pinch rolls 21 and 22 are coordinated in operation with the conveyor rolls 15 so that the pinch rolls 21 and 22 enter into engagement with the pipe 9 when the same has dropped slightly from the conveyor rolls 15 to the proper elevation for entering into swabbing registration within the mouth of the blow tube 18. Means for accomplishing this comprise electrically controlled pneumatic apparatus including a pneumatic operator 38 having a cylinder 39 with a piston 40 operative therein reciprocably and provided with a piston rod 41 appropriately connected to a bearing structure 42 on the shaft 28 of the pinch roll 21. Reciprocations of the piston 40 are effected by pressure fluid supplied from a suitable source through a supply duct 43 under the control of a valve 44 which is operable for alternately opening and closing appropriate passages leading from the supply duct 43 to opposite ends of the cylinder 39. A spring 47 normally biases the valve 44 in one direction while a solenoid operator 45 is operative when energized to move the valve 40 in the opposite direction in opposition to the bias of the spring 47. Herein the spring 47 normally acts to urge the valve 44 into the reverse position from that shown in Fig. 2, namely into the position wherein pressure fluid is delivered to the forward end of the cylinder 39 so as to drive the piston 40 away from the attached shaft 28 whereby the piston rod 41 draws the shaft 28 and thereby the pinch roll 21 toward the left as seen in Fig. 2, namely into the dot dash position shown which is the separated condition of the pinch rolls so that a pipe section 9 can be freely run into position therebetween. For reversing the piston, that is for driving the piston into the position shown in Fig. 2, the solenoid 45 is actuated by closing of a switch 48 in an electrical circuit 49 for supplying the solenoid with electrical energy from a source of electrical energy from an electrical supply circuit 59 which is also connected to the motor 35 for supplying the motor with electrical energy. It will be understood that the switch 48 while shown merely symbolically in the drawing, may be connected into or operated by any appropriate or desired means in coordination with and automatically as an incident to operation of the machine organization with which the pinch roll assembly 20 is utilized. In the copending application of the present applicant, Serial No. 28,494, filed May 21, 1948, now Patent No. 2,606,846, electrical circuits for synchronizing and integrating operation of the machine as a whole are disclosed in detail and the switch 48 may be readily incorporated into one of those circuits or operating means therefor. In any event when the switch 48 is closed, the solenoid operator 45 is energized and actuates the control valve 44 to drive the piston 4-0 into the position wherein the pinch roll 21 approaches the companion pinch roll 22 and thereby engages the pipe section 9 therebetween firmly but in cushioned relation by reason of the pneumatic fluid used for driving the piston. Pneumatic fluid is superior to hydraulic fluid for this use because of its cushioning quality whereby to compensate for any irregularities that may be present in the apparatus or in the engaged pipe section and thus avoid damaging the freshly coated external surface of the pipe section.

In the operation of the valve 44, exhaust from the cylinder 39 is controlled by an auxiliary valve section 51 on the valve 44 and which controls exhaust ducts leading from the opposite ends of the cylinder 39 to an exhaust outlet 52.

Swinging operations or oscillations of the pinch roll 21 as controlled by the pneumatic operator 38 are correlated with operations of the conveyor rolls 15 and of the blow tube 18 in the following fashion. When a freshly galvanized pipe section 19 has been advanced by the pinch rolls 14 and the conveyor rolls 15 to a position wherein the leading end of the pipe section has just reached the point where it will engage within the mouth of the waiting blow tube 18, that is the position shown in full line in Fig. l, the rolls 15 are deenergized to release the conduit section which by this time, of course, has been advanced into a position between the separated pinch rolls 21 and 22. Closely coordinated with release of the conduit section from the overhead conveyor rolls l5 and thereby slight dropping down of the forward end portion thereof, the switch 48 is closed, thereby effecting energization of the solenoid 45 and actuation of the control valve 44 and driving of the piston 40 to cause the shaft 28 to which connected to move laterally and drive the pinch roll 21 into pipe gripping relationship to the companion pinch roll 22. Throughout the operation of the machine, the motor 35 continues in operation to drive the pinch rolls 21 and 22 rotatably in the direction which upon engagement of the pinch rolls 21 and 22 with the pipe section therebetween will cause advancing movement or at least forward thrust of the pipe section.

Since at the moment the leading end of the pipe section 9 engages in thrusting relation within the mouth of the blow tube 18, it is desirable that the pinch rolls 21 and 22, similarly as the pinch rolls 14, cease rotating, or at least not move relative to the engaged pipe section 9, so as to avoid marring the engaged surface of the pipe. Slip clutch means could. be used for this purposesimilarly as in connection with the pinch rolls 14, but a practical expedient utilized for this purpose comprises having the motor 35 of the three phase type so that in the presence of predetermined resistance to turning of the motor, it will be held immovable, but yet remain under torque, without overheating. As a result, when the leading end of the pipe section comes to rest within the mouth of the blow tube 18, the pinch rolls 21 and 22 cease rotating but maintain their grip on the pipe section and continue imparting forward thrust to the pipe section which supplements the thrust of the pinch rolls 14 and assures that the leading end of the pipe section remains firmly and undisplaceably in substantially sealing engagement within the blow tube mouth so that full efficiency of the blast of internal swabbing fluid from the blow tube will result.

Promptly upon completion of the internal swabbing action, the blow tube 18 is retracted into the dash line position shown in Fig. l, by action of a fluid operated cylinder and piston actuator 53. Thereupon, the pinch rolls 14 and the pinch rolls 21 and 22 resume rotary activity and the blown pipe section 9 is advanced to clear the trailing end portion thereof from the pinch rolls 14. In correlation with this activity, the switch 48 is opened at the proper movement for breaking the energizing circuit to the solenoid 45, the valve 44 reverses, causing reversal of the piston 40 and retraction of the pinch roll 21 for releasing the blown pipe section. The released pipe section drops down onto a conveyor 54 as shown in Fig. l and is carried on to a discharge point away from the machine. In the meantime a succeeding pipe section 9 to be swabbed is advanced toward and into swabbing position and the cycle of operation resumed.

Inasmuch as chilling of the pipe sections 9 to be swabbed should be avoided, means are preferably provided for heating the pinch rolls 21 and 22. For this purpose electrical heating may be resorted to, the pinch rolls being provided with internal electrical heating units 55 supplied with electrical energy from a supply circuit 57 operatively associated with the electrical heating units 55 through the medium of appropriate commutator assemblies 58 carried by the drive shafts 28 for the pinch rolls.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In combination in a pipe handling pinch roll assembly, upright supporting means, a pair of substantially parallel vertical shafts carried by said supporting means, a separate pinch roll carried at the lower end of each of the shafts, the pinch rolls being disposed on substantially vertical axes, means for driving said pinch rolls in operative unison, and means for relatively angularly moving said shafts to separate and operatively close said pinch rolls for releasing and engaging successive sections of pipe therebetween while the upper ends of the shafts remain substantially fixed.

2. In combination in a pinch roll assembly of the character described, an upright supporting structure, a pair of substantially parallel vertical shafts coextensively supported by said supporting structure from adjacent to the upper ends of the shafts and with the lower ends of the shafts depending to a substantial distance, respective pinch rolls carried by said shafts in side by side relation, means adjacent to the upper ends of the shafts for driving the shafts in unison, and means adjacent to the lower portions of the shafts for angularly oscillating one of the shafts to carry the pinch roll supported thereby toward and away from the companion pinch roll while the upper end of said one of said shafts remains substantially fixed in position.

3. In combination in a pinch roll assembly of the character described, an upright supporting structure, a pair of substantially parallel vertical shafts coextensively supported by said supporting structure from adjacent to the upper ends of the shafts and with the lower ends of the shafts depending to a substantial distance, respective pinch rolls carried by said shafts in side by side relation, means adjacent to the upper ends of the shafts for driving the shafts in unison, and means adjacent to the lower portions of the shafts for angularly oscillating one of the shafts to carry the pinch roll supported thereby toward and away from the companion pinch roll while the upper end of said one of said shafts remains substantially fixed in position, said last mentioned means comprising a pneumatic operator.

4. In combination in a pipe handling pinch roll assembly of the character described, an upright supporting structure, a pair of substantially parallel vertical depending shafts supported relatively rockably by the upper portion of the supporting structure, respective pinch rolls carried by the lower ends of the shafts, means adjacent to the upper ends of the shafts for driving the same in unison and comprising a three phase motor operative to come to a halt in response to predetermined resistance while remaining in torque, and means for relatively angularly swinging the shafts to bring the pinch rolls into and out of engagement with a pipe section while the upper ends of the shafts remain substantially fixed.

5. In combination in a pinch roll assembly of the character described, an upright supporting structure, a pair of substantially parallel vertical coextensive shafts having rolls at the lower ends thereof and having upper end portions thereof bearingly supported in rockable relation at the upper portion of said supporting structure, means at the upper end portions of the shafts for driving the same in unison, means adjacent the lower end portion of one of said shafts for mounting the same to said supporting structure in an angularly rockably adjustable relation to said supporting structure, and means adjacent to the lower portion of the remaining shaft including a control unit for angularly rockably actuating said remaining shaft to swing the lower end portion thereof toward and away from said one shaft while the upper ends of said shafts remain substantially fixed, said driving means being unaffected by the adjustment or swinging of the respective shafts.

6. In combination in a pinch roll assembly for handling hot freshly galvanized pipe sections in a swabbing apparatus, a supporting structure, a pair of substantially parallel vertical depending shafts supported adjacent their upper end by said supporting structure and having coextensive pinch rolls at their lower ends, means for heating said rolls to prevent chilling freshly galvanized pipe, and means for relatively angularly swinging said shafts while the upper ends thereof remain substantially fixed and to move the rolls into and out of gripping relation to a pipe section.

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